Tripsacum dactyloides x Miscanthus sacchariflorus plant named ‘Mammoth’

ABSTRACT

A new cultivar of Tripsacum dactyloides x Miscanthus sacchariflorus plant named ‘Mammoth’ that is characterized by its highly vigorous growth habit, its very tall plant height, its strong upright stems that do not fall over or flop, its leaves that are green in color with white center veins, and its lack of flower production.

Botanical classification: Tripsacum dactyloides x Miscanthussacchariflorus.

Cultivar designation: ‘Mammoth’.

CROSS-REFERENCE TO A RELATED APPLICATION

This application claims priority to European Community Plant VarietyOffice (CPVO) Plant Breeder's Rights Application No. 2022/0164 filed onJan. 18, 2022 under 35 U.S.C. 119(f), the entire contents of which isincorporated by reference herein.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar ofTripsacum dactyloides x Miscanthus sacchariflorus and will be referredto hereafter by its cultivar name, ‘Mammoth’. ‘Mammoth’ represents a newcultivar of ornamental grass grown for landscape use.

The new cultivar resulted from a controlled breeding program conductedby the Inventor in Boskoop, The Netherlands. The goal of the breedingprogram was to develop a new ornamental grass with a vigorous growthhabit and strong and tall that does not lodge (fall over). The Inventormade a cross in autumn of 2008 between unnamed and unpatentedproprietary plants of Tripsacum dactyloides (female parent) andMiscanthus sacchariflorus (male parent) from the Inventor's breedingprogram. ‘Mammoth’ was selected as a single unique plant in summer 2010from the resulting seedlings of the above cross.

Asexual propagation of the new cultivar was first accomplished by rootcuttings by the Inventor in Boskoop, The Netherlands in autumn of 2010.Asexual propagation by root cuttings has determined that thecharacteristics of the new cultivar are stable and are reproduced trueto type in successive generations.

SUMMARY OF THE INVENTION

The following traits have been repeatedly observed and are determined tobe the characteristics of the new cultivar. These attributes incombination distinguish ‘Mammoth’ as a unique cultivar of ornamentalgrass.

-   -   1. ‘Mammoth’ exhibits a highly vigorous growth habit.    -   2. ‘Mammoth’ exhibits a very tall plant height.    -   3. ‘Mammoth’ exhibits strong upright stems that do not fall over        or flop.    -   4. ‘Mammoth’ exhibits leaves that are green in color with white        center veins.    -   5. ‘Mammoth’ exhibits no production of flowers.

The female parent of ‘Mammoth’ differs from ‘Mammoth’ in producingflowers and having a less vigorous plant habit, a shorter plant height,a more mounded plant shape, stems that are less upright that tend toflop and leaves that do not have a white center vein. The male parent of‘Mammoth’ differs from ‘Mammoth’ in producing flowers and in having amuch less vigorous plant habit, a much shorter plant height, leaves thatare more narrow, and produces flowers. ‘Mammoth’ can be most closelycompared to the cultivars Miscanthus x giganteus ‘Aksel Olsen’ (notpatented) and Miscanthus sacchariflorus ‘Robustus’ (not patented).‘Aksel Olsen’ is similar to ‘Mammoth’ in foliage color. ‘Robustus’ issimilar to ‘Mammoth’ in plant shape and foliage color. ‘Aksel Olsen’ and‘Robustus’ both differ from ‘Mammoth’ in having less vigorous growthhabits, shorter plant heights, and in producing flowers.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying color photographs illustrate the overall appearance anddistinct characteristics of the new ornamental grass. The photographswere taken in November of plants 5 years in age as field grown inBoskoop, The Netherlands.

The photograph in FIG. 1 . was taken of a row of ‘Mammoth’ plants andprovides a view of the overall plant habit and general appearance of‘Mammoth’.

The photograph in FIG. 2 . provides a close-up view of the foliage of‘Mammoth’.

The photograph in FIG. 3 . provides a close-up view of the stems of‘Mammoth’.

The colors in the photographs are as close as possible with thephotographic and printing technology utilized and the color values citedin the Detailed Botanical Description accurately describe the colors ofthe new ornamental grass.

DETAILED BOTANICAL DESCRIPTION

The following is a detailed description of 5-year-old plants of the newcultivar as field grown in Boskoop, The Netherlands. The phenotype ofthe new cultivar may vary with variations in environmental, climatic,and cultural conditions, as it has not been tested under all possibleenvironmental conditions. The color determination is in accordance withThe 2015 Colour Chart of The Royal Horticultural Society, London,England, except where general color terms of ordinary dictionarysignificance are used.

-   General description:    -   -   Plant type.—Herbaceous perennial grass.        -   Plant habit.—Very upright with stems that do not lodge.        -   Height and spread.—Average of 53 m in height and 22 m in            spread as a 5-year-old plant in the landscape.        -   Cold hardiness.—At least in U.S.D.A. Zone 6.        -   Diseases and pests.—No susceptibility or resistance to            diseases or pests has been observed.        -   Root description.—Fibrous.        -   Root development.—An average of 6 months to produce a young            rooted plant from a root cutting.        -   Propagation.—Root cuttings.        -   Growth rate.—Highly vigorous.-   Stem description:    -   -   General.—Rounded, strong.        -   Stem aspect.—Growing from the base, held upright,            vertically.        -   Stem quantity.—Average of 12 basal shoots and 1 lateral per            basal shoot.        -   Stem color.—Young; 145C, mature; 148B, matte down 195A to            195D, internodes 146A and 146B, tinged 153D and 167D, older            stems 153D, tinged 167D.        -   Stem size.—An average of 46 m in length (from base of shoots            to base of inflorescence), 1.9 cm in diameter.        -   Stem surface.—Both surfaces moderately glossy and covered            with a matte down.-   Foliage description:    -   -   Leaf shape.—Linear.        -   Leaf division.—Simple.        -   Leaf base.—Sheathed.        -   Leaf apex.—Narrow and long acuminate.        -   Leaf aspect.—Slightly carinate, moderately arching.        -   Leaf venation.—Parallel, main vein furrowed, upper surface            color 155C, lower surface color N144A.        -   Leaf margins.—Entire, visibly smooth, when rubbed downwards            becoming very sharp.        -   Internode length.—An average of 21.9 cm.        -   Leaf size.—An average of 83.3 cm in length, an average of            3.2 cm in width, sheath; 21.9 cm in length, 2.2 cm in width            (folded open).        -   Leaf surface.—Upper and lower surface glabrous and smooth,            non-rugose, ligules; moderately pubescent with thin hairs an            average of 1.5 mm in length and 156D in color.        -   Leaf number.—An average of 14 per shoot.        -   Leaf arrangement.—Alternate.        -   Leaf color.—Young upper surface; 144A, young lower surface            143A and 144A, mature upper and lower surface NN137C,            sheath; inner side 194B, outer side 146B.-   Flower description: No flowers have been produced to date.

It is claimed:
 1. A new and distinct cultivar of Tripsacum dactyloides xMiscanthus sacchariflorus plant named ‘Mammoth’ as herein illustratedand described.